Printed circuit board substrate comprising a coated boron nitride

Patent metadata

Field	Value
Publication number	US-11895768-B2
Application number	US-201917641548-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Oct 2, 2018
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

In an embodiment, a printed circuit board substrate ( 12 ) comprises a polymer matrix; a reinforcing layer ( 42 ); and a plurality of coated boron nitride particles ( 44 ); wherein the plurality of coated boron nitride particles comprise a coating having an average coating thickness of 1 to 100 nanometers. The polymer matrix can comprise at least one of an epoxy, a polyphenylene ether, polystyrene, an ethylene-propylene dicyclopentadiene copolymer, a polybutadiene, a polyisoprene, a fluoropolymer, or a crosslinked matrix comprising at least one of triallyl cyanurate, triallyl isocyanurate, 1,2,4-trivinyl cyclohexane, trimethylolpropane triacrylate, or trimethylolpropane trimethacrylate.

First claim

What is claimed is:

1. A printed circuit board substrate comprising:
a polymer matrix, wherein the polymer matrix comprises at least one of an epoxy, a polyphenylene ether, a polystyrene, an ethylene-propylene dicyclopentadiene copolymer, a polybutadiene, a polyisoprene, a fluoropolymer, or a crosslinked matrix comprising at least one of triallyl cyanurate, triallyl isocyanurate, 1,2,4-trivinyl cyclohexane, trimethylolpropane triacrylate, or trimethylolpropane trimethacrylate;
a reinforcing layer; and
10 to 50 volume percent, based on the total volume of the printed circuit board substrate, of a plurality of coated boron nitride particles having an average particle size of 5 to 500 micrometers;
wherein the plurality of coated boron nitride particles comprises a coating comprising aluminum oxide, wherein the coating has an average coating thickness of 0.5 to 10 nanometers, wherein the plurality of coated boron nitride particles further comprises a surface treatment;
wherein the printed circuit board substrate has a peel strength of greater than or equl to 3 pli as determined in accordance with IPC-Tm-650-2,4,8; and
wherein the printed circuit board has a Z-direction thermal conductivity that is at least 90% that of an equivalent printed circuit board comprising boron nitride particles without the coating comprising aluminum oxide.

2. The printed circuit board substrate of claim 1 , wherein the plurality of coated boron nitride particles has an average particle size of 10 to 250 micrometers.

3. The printed circuit board substrate of claim 1 , wherein the coating further comprises silicon dioxide.

4. The printed circuit board substrate of claim 1 , wherein the average coating thickness is 1 to 10 nm.

5. The printed circuit board substrate of claim 1 , wherein the coating is disposed over 10 to 100 A % of the total surface area of the plurality of the boron nitride particles.

6. The printed circuit board substrate of claim 1 , wherein the plurality of coated boron nitride particles comprises less than 1 wt % of the coating based on the total weight of the plurality of coated boron nitride particles.

7. The printed circuit board substrate of claim 1 , wherein the plurality of coated boron nitride particles comprises atomic layer deposition coated particles.

8. The printed circuit board substrate of claim 1 , wherein the printed circuit board substrate comprises 10 to 25 vol % of the plurality of coated boron nitride particles based on the total volume of the printed circuit board substrate.

9. The printed circuit board substrate of claim 1 , wherein the printed circuit board substrate comprises 15 to 99 vol % of the thermoset polymer matrix based on the total volume of the printed circuit board substrate.

10. The printed circuit board substrate of claim 1 , wherein the reinforcing layer comprises a plurality of glass fibers.

11. The printed circuit board substrate of claim 1 , wherein the polymer matrix comprises at least one of a butadiene homopolymer, an isoprene homopolymer, a butadiene-vinylaromatic copolymer, or an isoprene- vinylaromatic copolymer.

12. The printed circuit board substrate of claim 1 , wherein the surface treatment comprises a coupling agent.

13. The printed circuit board substrate of claim 1 , comprising, based on the total volume of the printed circuit board substrate:
15 to 50 volume percent of the polymer matrix;
10 to 25 volume percent of the plurality of coated boron nitride particles;
20 to 50 volume percent of a secondary inorganic filler comprising
a secondary inorganic dielectric filler, and
a flame retardant filler; and

the reinforcing layer.

14. The printed circuit board of claim 13 , wherein:
the polymer matrix comprises at least one of a polystyrene, an ethylene-propylene dicyclopentadiene copolymer, a polybutadiene, an epoxy, or a polyisoprene,
the reinforcing layer comprises glass fibers;
the plurality of coated boron nitride particles further comprise a surface treatment comprising a coupling agent; and
the secondary inorganic dielectric filler comprises silica.

15. A circuit material comprising the printed circuit board substrate of claim 1 and a conductive layer disposed on at least one surface of the printed circuit board substrate.

16. A method of making the printed circuit board substrate of claim 1 , comprising
forming a mixture comprising a thermosetting composition and the plurality of the coated boron nitride particles;
coating a reinforcing layer with the mixture; and
curing the thermosetting composition to form the printed circuit board substrate.

17. The method of claim 16 , wherein the reinforcing layer comprises a plurality of glass fibers.

18. The method of claim 17 , further wherein the coating the reinforcing layer comprises roll-to-roll coating the reinforcing layer with the mixture by first unrolling the reinforcing layer from a first roll, traversing the reinforcing layer through the mixture, traversing the reinforcing layer through a solvent drying section and at least partially curing the thermosetting mixture, and winding the coated reinforcing layer onto a second roll.

19. The method of claim 16 , wherein the curing comprises partially curing to form a pre-preg.

20. The method of claim 16 , further comprising depositing a conductive layer on at least one surface of the printed circuit board substrate.

21. The method of claim 16 , further comprising depositing the coating on the plurality of boron nitride coated particles by atomic layer deposition prior to forming the mixture.

Assignees

• Rogers Corp

Inventors

• Kim Eui Kyoon
• Fitts Bruce
• Brown Christopher

Classifications

• H05K1/0204 Primary

  using means for thermal conduction connection in the thickness direction of the substrate (H05K1/0207 takes precedence) · CPC title

• C23C16/403

  of aluminium, magnesium or beryllium · CPC title

• C23C16/45525

  Atomic layer deposition [ALD] · CPC title

• H05K1/0366

  reinforced, e.g. by fibres, fabrics (H05K1/036 takes precedence) · CPC title

• H05K1/0373 Primary

  containing additives, e.g. fillers (H05K1/036 takes precedence) · CPC title